Electrical connector, LED assembly, and method of assembly therefor

ABSTRACT

An electrical connector for connecting multiple light emitting diodes (LEDs) in parallel to a two-wire electrical supply bus, made up of upper and lower halves that snap together and contact pins that pass through holes in the upper half to make insulation displacement connections with the conductors of the supply bus. Assemblies including large numbers of LEDs are made by snapping connectors onto the bus, inserting contacts into the connectors, and connecting LEDs to the contact pins, although not necessarily in that order. The contact pins may be hollow to receive the LED leads. Also, the positions of the holes in the upper halves of the connectors, and therefore of the contact pins, may be staggered, so that the spacing between the contacts can be made equal to the pitch between the leads of the LEDs without spacing the conductors of the supply bus further apart.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for lighting. Moreparticularly: the invention relates to a system alternately employinglight emitting diodes (LEDs) or a light source guided through opticalfibers.

2. Discussion of the Background

Signs and pictures can benefit from being illuminated, either foraesthetic reasons, or for visibility. In particular, outdoor signs mayneed to be illuminated to be read after darkness. Almost everyone hashad the experience of trying to locate a residential address after darkwith only the benefit of car headlights. Illuminated signs fordisplaying house numbers are widely known, but have not found widespreadpopularity. Known signs of this type tend to be heavy, bulky and consumeexcessive electrical power. The householder must normally either arrangefor the sign to be wired into the house electrical supply or be preparedto frequently replace batteries or bulbs. Some form of light-sensitiveswitching may need to be incorporated to reduce power consumption,thereby adding complexity and bulk. In addition, it is undesirable tohave external electrical wiring, which is exposed to the vagaries of theweather. There is a need for house number signs that inherently consumeless power, as well as for signs that can be illuminated without havingelectrical wiring outside the house.

The above and other disadvantages of the background art are overcome bythe teachings of the present invention, as will be discussed below.

SUMMARY OF THE INVENTION

The present invention provides for a system of object lighting that mayoptionally employ either multiple Light Emitting Diodes (LEDs) connectedto an electrical bus via Insulation Displacement Connectors (IDC), oralternatively a central light source with light beams distributedthrough optical fibers via a splitter to a number of lenses providingpoint light sources equivalent to the LEDs.

Various lighting configurations may be achieved by the system of theinvention. These include signs and pictures illuminated by point lightsources arranged around a periphery thereof and configured to bereflected via a rear mirrored surface. This arrangement is particularlywell adapted to illuminate house numbers, but may be used to illuminateany sign or picture.

In another aspect of the invention, a lens system is provided for pointlight sources, so that either LEDs or optical fiber light sources canprovide the same illumination pattern. A small lens is configured to fiton the end of each optical fiber and provide the same outer curvature asa standard LED, and a larger lens is configured to fit either a standardLED or the small lens internally. In this manner, similar beams of lightare produced regardless of whether LEDs or optical fibers are employed,and therefore optical fibers may be substituted for LEDs or vicea versawithout affecting the way the light is distributed.

In a further aspect of the invention, electrical connectors are providedto connect a plurality of LEDs to an electrical bus by displacement ofthe insulation. This enables a relatively large number of LEDs to beconnected onto an electrical wiring harness or power supply bus with aminimum amount of wiring and a minimum number of assembly operations.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described with reference to thedrawings, in which like numerals designate like elements, and in whichany dimensions given are by way of example.

FIG. 1 is a plan view of a fiber optical splitter according to apreferred embodiment of the invention.

FIG. 2 is a pictorial view of a fiber optical splitter according to apreferred embodiment of the invention.

FIG. 3 is an end view of a lower half of a fiber optical splitteraccording to a preferred embodiment of the invention, when viewedthrough section III—III.

FIG. 4 is a sectional side view of a small lens according to a preferredembodiment of the invention.

FIG. 5 is a sectional side view of a large lens according to a preferredembodiment of the invention.

FIG. 6 is an isometric view of an electrical connector according to apreferred embodiment of the invention.

FIG. 7 is an end view of an electrical connector according to apreferred embodiment of the invention.

FIG. 8 is a side view of an electrical connector according to apreferred embodiment of the invention.

FIG. 9 is a plan view of an electrical connector according to apreferred embodiment of the invention.

FIG. 10 is a pictorial view of a light panel according to the invention,showing a diffuser sheet removed.

FIG. 11 is a sectional view through section XI—XI of FIG. 10.

FIG. 12 is an exploded isometric view in greater detail of a light paneledging strip according to the invention.

FIG. 13 is a side view of the light panel edging strip of FIG. 12.

FIG. 14 is an isometric view of a light box according to a furtherembodiment of the invention

FIG. 15 is an exploded side view of the light box of FIG. 14.

FIG. 16 is a block diagram of an arrangement for distributing lightbeams by using the splitter of FIGS. 1–3.

FIG. 17 is a detailed view showing the use of the small lens of FIG. 4with the splitter.

DETAILED DESCRIPTION OF THE DRAWINGS

A light panel 1000 according to a preferred embodiment of the inventionis shown in FIG. 10. Light panel 1000 includes a mirrored back sheet1010, an edging strip 1020, a frontal diffuser sheet 1030 and aplurality of point light sources 1040. The diffuser sheet 1030 is shownremoved from the light panel 1000 in this view for clarity. FIG. 11shows the light panel 1000 fully assembled, but without point lightsources 1040, when viewed on section XI—XI of FIG. 10. Both the diffusersheet 1030 and the mirrored back sheet 1010 may be made from acrylic, orfrom any other suitable material. Point light sources 1040 are insertedin apertures 1050 in edging strip 1020. Edging strip 1020 is preferablymade of rust proof steel with a Chrome plated or otherwise mirroredinner surface 1070, but may be made from other suitable materialswithout departing from the scope of the invention.

The edging strip 1020 is arranged to overlap the diffuser sheet 1030 andthe backing sheet 1010 by a distance ‘d’, which in a non-limitingexample may be 0.375 inches, and an inner surface 1070 of edging strip1020 is angled downwards by an angle ‘a’. Angle ‘a’ is preferably in therange 10–15°, preferably substantially 12°, i.e. angle ‘b’ would besubstantially 78°, such that light from point light sources 1040 isreflected from mirrored surface 1060 of back sheet 1010 towards diffusersheet 1030. As the point light sources 1040 are arranged to emit lightnormal to the inner surface 1070, the angle of incidence of the lightwith respect to the mirrored surface 1060 of the backing sheet 1010 isalso equal to the angle ‘a’. The diffuser sheet 1030 may be covered by afurther sheet acting as a mask (not shown), which does not permit thepassage of light except through selective openings, such as cut outnumerals and/or letters, for example to display a house number or othermessage. In an alternative embodiment, the light panel may be used as apicture frame and the mask may be the mat used in framing the picture.This results in an appealing backlighting effect.

Angle ‘a’ may, of course, be varied outside of the range from 10–15°without departing from the scope of the invention. Inner surface 1070 ofedging strip 1020 is also preferably mirrored to maximize internalreflection of the light. This arrangement allows height ‘h’ in anon-limiting example to be as low as 0.675 inches, which issignificantly less than the thickness of light panels known in thebackground art. Point light sources 1040 may be interchangeably providedeither by LEDs or by lenses connected by optical fibers to central lightsource 10.

FIG. 12 shows edging strip 1020 in greater detail, in an exploded viewtogether with cap 1080 and mounting bracket 1090, and FIG. 13 shows aside view of edging strip 1020. Tabs 1075 are provided on the samecenters as holes 1050, preferably at a spacing of 1 inch, although thespacing may be varied without departing from the scope of the invention.Brackets 1090 are provided with holes 1095 for receiving tighteningscrews (not shown) and are used to retain edging strip 1020 at thecorners of light panel 1000. When the corners of light panel 1000 areassembled, brackets 1090 are placed such that screwing the tighteningscrews into holes 1095 will push brackets 1090 against the inside ofridges 1085 in edging strip 1020. Brackets 1090 may be made of steel orany other suitable material. Tabs 1075 may be folded to secure backingsheet 1010 when the light panel 1000 is assembled. Cap 1080 may be madeof any suitable plastic or other material, and serves both to finish theappearance of lighting panel 1000 and to cover the wiring or opticalfibers leading to point light sources 1040.

In a first embodiment, LEDs may be used for each point light source.Power for the LEDs may be derived from the mains wiring, or fromrechargeable batteries connected to a solar cell, or from any othersuitable source. Conventionally, this has involved soldering two wiresto each LED, which has necessitated a large number of separate solderingoperations to assemble a lighting system employing multiple LEDs.

In a preferred embodiment, the present invention overcomes this problemby using low-profile connector 600, as shown in FIGS. 6, 7, 8 and 9.Connector 600 includes an upper part 610 and a lower part 620, which maybe molded from a non-conductive thermoplastic such as ABS, or otherwiseformed from any suitable material. When upper and lower parts 610 and620 are assembled together, as shown in the drawings, two cylindricalrecesses 630 are formed, through which a wiring harness having twoinsulated wires 640 may be passed, each including an insulation layer645 surrounding an inner conductor 650. The inner conductors 650 may be,for example 24 AWG. Upper and lower parts 610 and 620 may, for example,be snapped together by using a simple hand tool (not shown).

Two holes 660 are provided in upper part 610 of connector 600, intowhich pins 670 are inserted. Holes 660 are placed in a staggeredrelationship relative to wires 640, so that the spacing ‘s’ is equal tothe spacing between the leads of the LED, for example 0.1 inches. Asingle pin 670 is shown removed from hole 660 in FIG. 8, and is hollow,with a central aperture 675 extending from an upper end, and a point 680at a lower end thereof. The central aperture 675 is sized to receive alead of an LED as a push fit, and the pins are configured to be a pushfit into holes 660. Pins 670 may be made of brass or any other suitablematerial. The leads of an LED (not shown) are inserted into centralapertures 675 in pins 670, which are then inserted through holes 660 inupper part 610 of connector 600, and the points 680 of pins 670penetrate the outer insulation layers 645 of wires 640, to make contactwith the inner conductors 650 thereof. In one example, the overall sizeof the connector 600 is 0.25 inches wide and 0.1875 inches high.

Large lens 500 shown in FIG. 5 has a planar rear surface 510 and aconvex front surface 520. Front surface 520 has substantially the samecurvature as inside surface 530, which is configured to mate with frontsurface 420 of small lens 400. Surfaces 520 and 530 are highly polished.Inner cylindrical surface 540 of large lens 500 is configured to have aparticular diameter so that both the optical fibers and the ferrule of astandard LED are a push fit. Thus, either a small lens 400 (see FIG. 4)or a standard LED may be interchangeably push fit into large lens 500,and in both cases the focal point of the large lens 500 substantiallycoincides with the focal point of the light source.

FIGS. 14 and 15 show a light box 1400 according to an embodiment of theinvention. Light box 1400 includes a holder 1410, a clear cover 1420, anend cap 1430, a light source 1440 and top and bottom reflective dishes1450. Holder 1410 is preferably made from black brushed Aluminum, butmay be made of any other suitable material, and has a reflectiveback-plate 1460. Top and bottom reflective dishes 1450 may, for example,be made of a suitable plastic with a reflective metal coating. The clearcover 1420 may be made of plexiglass or the like, and the end cap may bean Aluminum stamping, although other materials may be used. Each lightsource 1440 may include a large lens 500 inside which is inserted eitheran LED or a small lens 400 connected via optical fibers to a centrallight source 10. Multiple light boxes 1400 may, for example, be used foroutdoor landscape lighting, or for indoor decorative lighting. These maybe connected as shown in FIG. 16.

In an alternative embodiment of the invention, illustrated in FIG. 16, acentral light source 10, which may be a halogen lamp or any othersuitable light source, is used to illuminate a first end of a bundle ofoptical fibers 50. The fibers are then separated in a splitter 100, andstrands of optical fibers 60 are fed to light boxes 1400 or to lightingstrip 1800 as appropriate, as will be discussed further.

Splitter 100 is shown in more detail in FIGS. 1, 2 and 3. Splitter 100may be constructed in upper and lower halves 110, 120, fastened togetherby screw 130 located in aperture 135, or by any other suitable means.The bundle of fibers 50 from the light source 10 enter the splitter 100through input aperture 140 and exit through a plurality of outputapertures 150, thereby splitting the light from the light source. Theoptical fibers are additionally aligned by apertures 160 in web 170.

FIG. 17 shows in more detail how each fiber strand 60 passes firstthrough an aperture 160 in the web 170 in the splitter 100 (only part ofwhich is shown), then through a ferrule 70 which protrudes through ahole 150. Ferrule 70 may be made of brass or any other suitablematerial, and is retained in place by web 170. Coupler 75 mates withferrule 70, and is connected through fiber strand 60 to a small lens 400retained in a lens assembly 80. Small lens 400 may in turn be inserted nlarge lens 500 as shown.

Small lens 400 is shown in more detail in FIG. 4. The end of the fiber60 and the rear surface 410 of small lens 400 are each polished beforethey are coupled together, e.g. with a suitable optical adhesive in lensassembly 80. The front surface 420 of small lens 400 is also highlypolished and has a convex curvature the same as that of a standard LEDto be used in other embodiments of the invention. The small lens 400therefore has a center of focus which is not only suitable for use withlarge lens 500 shown in FIG. 5, but is also suitable for use with astandard reflector (not shown) that is readily available and is designedto have a standard LED placed in the center thereof.

It is often desirable to illuminate an object without illuminating thesurroundings. For example, to enable a stair tread to be located withoutlighting an entire room. FIG. 16 shows a lighting strip 1800 accordingto another embodiment of the present invention, which can be used forthis and other similar purposes. Lighting strip 1800 includes a row ofpoint light sources 1840 that may be either LEDs or small lenses 400.Lighting strip 1800 may be connected to central light source 10 viasplitter 100 as also shown in FIG. 16.

It will be appreciated by one skilled in the art that numerousvariations and modifications are possible, and that the invention may bepractised otherwise than as specifically disclosed herein, withoutdeparting from the spirit and scope of the invention.

1. An electrical connector comprising: a first body part; a second bodypart configured to resiliently mate with said first body part; saidfirst and second body parts configured to receive insulated conductorstherebetween; and apertures formed in said first body part in adirection orthogonal to said insulated conductors, said aperturesconfigured to receive contacts; said apertures staggered in alongitudinal direction relative to said insulated conductors so as to beseparated by a first distance equal to a spacing between leads of alight source, where said spacing is greater than a second distancedefined laterally between adjacent said insulated conductors; whereinsaid contacts are configured to penetrate an insulation layer of saidinsulated conductors when said contacts are inserted into saidapertures; and wherein said contacts are at least partially hollow, eachof said contacts having a central aperture therein configured to receiveone of said leads of said light source within said aperture andlaterally surrounded by said aperture.
 2. The electrical connectoraccording to claim 1, further comprising: a first group of channelsformed in said first body part and configured to receive saidconductors; and a second group of channels formed in said second bodypart and configured to receive said conductors and to oppose said firstgroup of channels.
 3. The electrical connector according to claim 2,wherein: said first and second groups of channels each consist of a pairof channels.
 4. The electrical connector according to claim 3, wherein:said light source is a light emitting diode.
 5. The electrical connectoraccording to claim 1, wherein: said light source is a light emittingdiode.
 6. An assembly for connecting a plurality of light emittingdevices in parallel, said assembly comprising: an electrical supply bus,said bus comprising a pair of insulated electrical conductors; aplurality of electrical connectors configured to be resiliently attachedto said bus; said connectors each comprising first and second body partsconfigured to be resiliently fastened together; said first body partprovided with apertures in a direction orthogonal to said pair ofinsulated conductors to receive a pair of contacts; said aperturesstaggered in a longitudinal direction relative to said insulatedconductors so as to be separated by a first distance equal to a spacingbetween leads of said light emitting devices, where said spacing isgreater than a second distance defined laterally between said pair ofinsulated conductors; said pair of contacts configured to penetrate aninsulation layer of said insulated electrical conductors, said contactsconfigured to receive leads of said light emitting devices; wherein saidcontacts are at least partially hollow, each of said contacts having acentral aperture therein configured to receive one of said leads of saidlight source within said aperture and laterally surrounded by saidaperture.
 7. The assembly according to claim 6, wherein: said lightemitting devices are light emitting diodes.
 8. The assembly according toclaim 6, wherein: said pair of insulated conductors are conjoinedmechanically along at least part of a length of said conductors.
 9. Amethod of connecting a plurality of light emitting devices in parallel,said method comprising the steps of: providing an electrical supply bus,said bus comprising a pair of insulated electrical conductors; attachinga plurality of electrical connectors to said bus; providing first andsecond parts of said connectors; resiliently fastening together saidfirst and said second body parts of said connectors, providing in eachsaid first body part an aperture in a direction orthogonal to each ofsaid pair of insulated conductors to receive an electrical contact; saidapertures staggered in a longitudinal direction relative to saidinsulated conductors so as to be separated by a first distance equal toa spacing between leads of said light emitting devices, where saidspacing is greater than a second distance defined laterally between saidpair of insulated conductors; penetrating an insulation layer of eachsaid insulated electrical conductor with said electrical contact, andconnecting leads of said light emitting devices to each said contact;said step of connecting said leads further comprising inserting eachsaid lead into a central aperture within each said contact, such thateach said lead is laterally surrounded by each said central aperture.10. The method according to claim 9, wherein: said light emittingdevices are light emitting diodes.
 11. The method according to claim 9,wherein: said pair of insulated conductors are conjoined mechanicallyalong at least part of a length of said conductors.